Non-infectious fever in the neurological intensive care unit: incidence, causes and predictors

Temperature Control in Acute Brain Injury: An Update

Temperature control in severe acute brain injury (SABI) is a key component of acute management. This manuscript delves into the complex role of temperature management in SABI, encompassing conditions like traumatic brain injury (TBI), acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), aneurysmal subarachnoid hemorrhage (aSAH), and hypoxemic/ischemic brain injury following cardiac arrest. Fever is a common complication in SABI and is linked to worse neurological outcomes due to increased inflammatory responses and intracranial pressure (ICP). Temperature management, particularly hypothermic temperature control (HTC), appears to mitigate these adverse effects primarily by reducing cerebral metabolic demand and dampening inflammatory pathways. However, the effectiveness of HTC varies across different SABI conditions. In the context of post-cardiac arrest, the impact of HTC on neurological outcomes has shown inconsistent results. In cases of TBI, HTC seems promising for reducing ICP, but its influence on long-term outcomes remains uncertain. For AIS, clinical trials have yet to conclusively demonstrate the benefits of HTC, despite encouraging preclinical evidence. This variability in efficacy is also observed in ICH, aSAH, bacterial meningitis, and status epilepticus. In pediatric and neonatal populations, while HTC shows significant benefits in hypoxic-ischemic encephalopathy, its effectiveness in other brain injuries is mixed. Although the theoretical basis for employing temperature control, especially HTC, is strong, the clinical outcomes differ among various SABI subtypes. The current consensus indicates that fever prevention is beneficial across the board, but the application and effectiveness of HTC are more nuanced, underscoring the need for further research to establish optimal temperature management strategies. Here we provide an overview of the clinical evidence surrounding the use of temperature control in various types of SABI.

A comparative study on the use of procalcitonin to distinguish between central fever and infectious causes of fever

Introduction

central fever is defined as elevated body temperature without any evidence of infection or drug reaction fever, and currently it has no definitive diagnostic criteria. The current study aims to assess the role of procalcitonin (PCT) in differentiating central fever from fever secondary to infections in patients with neurological insults.

Methods

we conducted a retrospective study of patients admitted with a neurological insult (brain trauma, brain tumors and cerebrovascular accidents) in a tertiary care hospital. All patients who developed fever 48 hours after admission and had procalcitonin, C-reactive protein (CRP), and Erythrocyte sedimentation rate (ESR) done as part of fever evaluation were assessed to include in the study.

Results

out of 70 patients who met inclusion criteria, 37 had infections identified and 33 had no source of infection. The mean age was 42.9 years (± 18) in the infectious group while 40.3 years (± 18.2) in the central fever group and there was male predominance in both groups. In the infectious group there were 25(67.6%) males vs. 12(32.4%) females while in non -infectious group, males vs. females were 18(54.5%) vs. 15(45.5%) and there was no difference in both group (p-value 0.26) Median procalcitonin (PCT) value was 0.09 ng/dl (IQR 0.05- 0.19) in patients with no identified cause of infection and 1.4 ng/dl (IQR 0.5-5.1) in patients with infections with a p-value of <0.001. Although CRP and ESR were low in patients with central fever as compared to those with infections, these differences did not reach statistical significance with p-value of CRP 0.18 and p-value of ESR 0.31 between two groups.

Conclusion

PCT levels were low in patients with central fever and may be considered as a useful biomarker to differentiate between infectious fever from non-infectious fever in patients with brain injury. This can prevent unnecessary antibiotic use in patients without infection.

Traumatic brain injury extending to the striatum alters autonomic thermoregulation and hypothalamic monoamines in recovering rats

The brain cortex is the structure that is typically injured in traumatic brain injury (TBI) and is anatomically connected with other brain regions, including the striatum and hypothalamus, which are associated in part with motor function and the regulation of body temperature, respectively. We investigated whether a TBI extending to the striatum could affect peripheral and core temperatures as an indicator of autonomic thermoregulatory function. Moreover, it is unknown whether thermal modulation is accompanied by hypothalamic and cortical monoamine changes in rats with motor function recovery. The animals were allocated into three groups: the sham group (sham), a TBI group with a cortical contusion alone (TBI alone), and a TBI group with an injury extending to the dorsal striatum (TBI + striatal injury). Body temperature and motor deficits were evaluated for 20 days post-injury. On the 3rd and 20th days, rats were euthanized to measure the serotonin (5-HT), noradrenaline (NA), and dopamine (DA) levels using high-performance liquid chromatography (HPLC). We observed that TBI with an injury extending to the dorsal striatum increased core and peripheral temperatures. These changes were accompanied by a sustained motor deficit lasting for 14 days. Furthermore, there were notable increases in NA and 5-HT levels in the brain cortex and hypothalamus both 3 and 20 days after injury. In contrast, rats with TBI alone showed no changes in peripheral temperatures and achieved motor function recovery by the 7th day post-injury. In conclusion, our results suggest that TBI with an injury extending to the dorsal striatum elevates both core and peripheral temperatures, causing a delay in functional recovery and increasing hypothalamic monoamine levels. The aftereffects can be attributed to the injury site and changes to the autonomic thermoregulatory functions.

Vasospasm risk following aneurysmal subarachnoid hemorrhage in older adults

OBJECTIVE

Cerebral arterial vasospasm is a dreaded sequela of aneurysm rupture and can result in significant narrowing of the surrounding vasculature and subsequent cerebral ischemia. Treatment interventions are associated with distinct side effect profiles, including the risk of thrombosis and worsened ischemia, which may be associated with increased mortality-especially in older adults. An improved understanding of the likelihood of vasospasm in elderly patients would enable clinicians and patients to better consider the risks and benefits of vasospasm prophylaxis in this vulnerable population. This retrospective chart review aimed to assess the relationship between age at onset and the incidence of cerebral vasospasm among patients treated at the University of North Carolina Medical Center with spontaneous aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Electronic health record data from the Epic Systems Corp. database, compiled by the Carolina Data Warehouse for Health, were analyzed for patients older than 18 years who were previously treated for an SAH secondary to aneurysm at the University of North Carolina Medical Center within the past 10 years, ranging from June 2011 through June 2021. Logistic regression was used to calculate odds ratios and to determine the association of age with the occurrence of vasospasm following aSAH.

RESULTS

Of the 386 cases analyzed, 149 patients (38.6%) were older than 65 years at the time of aSAH. A total of 192 of the 386 patients (49.7%) developed vasospasm within the first 3-21 days following aSAH. Among the patients who developed vasospasm, only 31 of 192 patients (16.1%) were older than 65 years at the time of aneurysm rupture. Odds ratio calculations revealed that older adults (> 65 years) were 8 times less likely to develop vasospasm compared to their younger counterparts (p < 0.0001; 95% CI 5.0-13.0).

CONCLUSIONS

This study found that older patients are less likely to develop cerebral vasospasm following aSAH than are younger individuals. Age-associated changes in arteriosclerosis, inflammatory responses, and CSF dynamics may mitigate vascular narrowing in response to aSAH. This finding suggests that the aSAH treatment and vasospasm prevention paradigms should be revised to minimize potentially unnecessary interventions and avoid adverse outcomes for older adults.

Antipyretic Efficacy of Bromocriptine in Central Fever: an Exploratory Analysis

BACKGROUND

'Central' fevers are thought to result from disruption of hypothalamic thermoregulatory pathways following severe brain injuries. Bromocriptine, due to its central dopamine receptor agonism, has been hypothesized to have antipyretic effect in this setting. However, clinical evidence for this off-label use is limited to a few case reports. In this retrospective cohort study, we analyzed the effect of bromocriptine administration on body temperature in acute brain injury patients with suspected central fever.

METHODS

We screened a cohort of adult patients that received bromocriptine in the neurologic-intensive care unit of a tertiary care hospital between January 2018 and December 2021. Indication of central fever was ascertained by review of clinical documentation. A generalized additive mixed model (GAMM) was used to model temperature as a function of time relative to bromocriptine initiation. We adjusted for potential confounding due to the following covariates: temperature recording method (invasive vs surface), concurrent antipyretic administration within 8 h, and surface cooling device use within 4 h of temperature measurement. Temperature-time function was modeled using a cubic spline with k = 10 knots.

RESULTS

A total of 33 patients were included in the analysis (14 women; mean age: 50 y, standard deviation 14 y). Median dose of bromocriptine was 7.5 mg (range 2.5-40) for a median of 13 d (range 5-160). Age and sex did not impact the function of temperature over time. Predicted temperatures were significantly (p < 0.05) higher by 0.4 °C with invasive compared to surface recording methods, lower by 0.2 °C in the presence of cooling device use and lower by 0.1 °C with concurrent antipyretic use. On adjusted analysis with the GAMM, there was decline (p < 0.05) in temperature following bromocriptine initiation by - 0.3 °C at 24 h, - 0.5 °C at 48 h, and - 0.7 °C at 72 h.

CONCLUSIONS

Bromocriptine use was associated with modest but statistically significant decline in temperature, with nadir at 72 h post initiation. The findings provide a data driven basis for prospective evaluation.

The Role of Nursing Care in the Management of Patients with Traumatic Subarachnoid Hemorrhage

Traumatic subarachnoid hemorrhage (tSAH) is a critical condition that requires comprehensive management to optimize patient outcomes. Nursing care plays a key role in the overall management of patients with tSAH via various aspects of care, including neurological assessment, monitoring, intervention, and education. In this review, we aim to evaluate the significant contributions of nursing care in managing patients with tSAH. Nurses perform initial neurological assessments, including the glasgow coma scale, pupil reactivity, vital signs, and sensory-motor evaluations. These assessments provide valuable information for early identification of deteriorating neurological status and prompt intervention. Additionally, nurses closely monitor intracranial pressure (ICP), cerebral perfusion pressure, and other hemodynamic parameters, assisting in the prevention and timely detection of secondary brain injury. For example, some strategies to manage ICP include elevating the head of the bed, maintaining adequate oxygenation and ventilation, administering proper medications, and ensuring fluid and electrolyte balance. Also, through careful monitoring, early recognition, and appropriate preventive measures, nursing care could prevent complications, including infections, deep vein thrombosis, and pressure ulcers. Furthermore, nursing care extends beyond physical management and encompasses psychosocial support for patients and their families. Nurses establish therapeutic relationships, providing emotional support, education, and counseling to alleviate anxiety, address concerns, and facilitate coping mechanisms. Education regarding medication management, lifestyle modifications, and the importance of regular follow-up enhances patient compliance and promotes long-term recovery.

Systemic Inflammation after Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is one of the most severe neurological disorders, with a high mortality rate and severe disabling functional sequelae. Systemic inflammation following hemorrhagic stroke may play an important role in mediating intracranial and extracranial tissue damage. Previous studies showed that various systemic inflammatory biomarkers might be useful in predicting clinical outcomes. Anti-inflammatory treatment might be a promising therapeutic approach for improving the prognosis of patients with aSAH. This review summarizes the complicated interactions between the nervous system and the immune system.

Evaluating the Potential of a New Low-Profile Urinary Catheter in Preventing Catheter-Associated Urinary Tract Infections: A Prospective Randomized Blinded Clinical Trial

Aim

To investigate the efficacy of a new low-profile catheter on incidence of the catheter-associated urinary tract infections (CAUTI) in comatose patients admitted to the intensive care unit.

Background

Catheter-induced urothelial injury is a key component in the development of urinary tract infections in catheterized patients.

Methods

In this prospective randomized blinded clinical trial, 80 patients requiring indwelling urinary catheterization were equally randomized to either the standard Foley catheter (control) or the low-profile catheter (experimental) group. The signs of urinary tract infection for comatose patients were considered (ie, ≥105 of colony-forming unit/milliliter of urine, hematuria, serum leukocytes, and body temperature) and recorded at baseline and on days 3 and 5 after catheterization. The analysis of covariance was applied by the SPSS-20 software at a 95% confidence level.

Results

An increasing proportion of patients with elevated urinary colony counts were seen in the Foley catheter group compared with the low-profile catheter group (12.5% vs 5%). However, there were no between-group differences in the urinary colony counts and body temperature after controlling for antibiotic doses and fluid intake. Patients in the low-profile catheter group had significantly lower rates of hematuria and serum leukocytes than those in the Foley catheter group.

Conclusion

A newly designed low-profile urinary catheter has demonstrated a trend toward reducing the incidence of CAUTI in patients with indwelling urinary catheters. Further studies with larger sample sizes and follow-up are needed to confirm the benefits.

The impact of fever as a testing indication on the detection rate of deep vein thrombosis in neurocritically ill patients

Aim

Deep vein thrombosis (DVT) is considered a possible source of non-infectious, non-central fever in the intensive care unit (ICU). In the neurocritically ill, it is unknown whether lower extremity venous Doppler ultrasonography (LEVDUS) for DVT in the setting of fever leads to a higher detection rate than the baseline detection rate of DVT in this population. The aim of this study was to compare the DVT detection rate of LEVDUS performed for the indication of fever to LEVDUS performed for other indications in a neurosciences ICU.

Methods

Requisition forms for all LEVDUS performed in a referral neurosciences ICU were reviewed and separated into those with "fever" as the stated reason for request and those with other stated reasons. The DVT detection rate was compared between these two categories of indications.

Results

Five hundred eleven LEVDUS were analyzed, of which 422 had been ordered for indications other than fever. Sixteen of these tests were positive, a detection rate of 3.8%. The remaining 89 LEVDUS had "fever" as the ordering indication. Six of these tests were positive for DVT, a detection rate of 6.7%. The likelihood of positivity of a test obtained as part of fever evaluation relative to one obtained for non-fever indications was not significantly different (OR, 1.83; 95% CI, 0.570-5.11; P = 0.246).

Conclusion

LEVDUS triggered by fever detected DVT at a numerically, but not statistically significantly higher rate than did LEVDUS performed for other indications in a neurocritically ill population. More rigorous investigation of this question is needed.

Development and validation of a nomogram to predict the 30-day mortality risk of patients with intracerebral hemorrhage

Background

Intracerebral hemorrhage (ICH) is a stroke syndrome with an unfavorable prognosis. Currently, there is no comprehensive clinical indicator for mortality prediction of ICH patients. The purpose of our study was to construct and evaluate a nomogram for predicting the 30-day mortality risk of ICH patients.

Methods

ICH patients were extracted from the MIMIC-III database according to the ICD-9 code and randomly divided into training and verification cohorts. The least absolute shrinkage and selection operator (LASSO) method and multivariate logistic regression were applied to determine independent risk factors. These risk factors were used to construct a nomogram model for predicting the 30-day mortality risk of ICH patients. The nomogram was verified by the area under the receiver operating characteristic curve (AUC), integrated discrimination improvement (IDI), net reclassification improvement (NRI), and decision curve analysis (DCA).

Results

A total of 890 ICH patients were included in the study. Logistic regression analysis revealed that age (OR = 1.05, P < 0.001), Glasgow Coma Scale score (OR = 0.91, P < 0.001), creatinine (OR = 1.30, P < 0.001), white blood cell count (OR = 1.10, P < 0.001), temperature (OR = 1.73, P < 0.001), glucose (OR = 1.01, P < 0.001), urine output (OR = 1.00, P = 0.020), and bleeding volume (OR = 1.02, P < 0.001) were independent risk factors for 30-day mortality of ICH patients. The calibration curve indicated that the nomogram was well calibrated. When predicting the 30-day mortality risk, the nomogram exhibited good discrimination in the training and validation cohorts (C-index: 0.782 and 0.778, respectively). The AUCs were 0.778, 0.733, and 0.728 for the nomogram, Simplified Acute Physiology Score II (SAPSII), and Oxford Acute Severity of Illness Score (OASIS), respectively, in the validation cohort. The IDI and NRI calculations and DCA analysis revealed that the nomogram model had a greater net benefit than the SAPSII and OASIS scoring systems.

Conclusion

This study identified independent risk factors for 30-day mortality of ICH patients and constructed a predictive nomogram model, which may help to improve the prognosis of ICH patients.

Fever management in acute brain injury

PURPOSE OF REVIEW

Fever is common after acute brain injury and is associated with poor prognosis in this setting.

RECENT FINDINGS

Achieving normothermia is feasible in patients with ischemic or hemorrhagic stroke, subarachnoid hemorrhage and traumatic brain injury. Pharmacological strategies (i.e. paracetamol or nonsteroidal anti-inflammatory drugs) are frequently ineffective and physical (i.e. cooling devices) therapies are often required. There are no good quality data supporting any benefit from therapeutic strategies aiming at normothermia in all brain injured patients when compared with standard of care, where mild-to-moderate fever is tolerated. However, recent guidelines recommended fever control in this setting.

SUMMARY

As fever is considered a clinically relevant secondary brain damage, we have provided an individualized therapeutic approach to treat it in brain injured patients, which deserved further validation in the clinical setting.

Nanopore 16S sequencing enhances the detection of bacterial meningitis after neurosurgery

Objective

Nosocomial bacterial meningitis is one of the major complications after neurosurgery. We performed nanopore 16S amplicon sequencing from cerebrospinal fluid (CSF) to evaluate bacterial meningitis in patients who underwent neurosurgery.

Methods

Among the patients who visited the neurosurgery department of Seoul National University Hospital between July 2017 and June 2020, those with clinically suspected bacterial meningitis were included. 16S rDNA PCR was performed from the CSF, and nanopore sequencing was performed for up to 3 h. The reads were aligned to the BLAST database. In each case, the culture and the 16S rRNA gene amplicon analysis were simultaneously performed and compared with each other, and we retrospectively reviewed the medical records. Genuine infection was determined by the identical results between conventional culture study and the sequencing, or clinically determined in cases with inconsistent results between the two methods.

Results

Of the 285 samples obtained from 178 patients who had 16S rDNA PCR, 41 samples (14.4%) were diagnosed with genuine infection. A total of 56.1% (23/41) of the samples with genuine infection showed a false‐negative culture test. In particular, 16S amplicon sequencing was useful in evaluating patients at the initial tests who had infection with intraventricular hemorrhage (Culture false‐negative rate = 100%), subarachnoid hemorrhage (Culture false‐negative rate = 77.8%), and systemic cancer (Culture false‐negative rate = 100%), which are risk factors for central fever. Moreover, 16S amplicon sequencing could suggest the possibility of persistent bacterial meningitis in empirical antibiotic use.

Conclusion

CSF nanopore 16S sequencing was more effective than conventional CSF culture studies in postoperative bacterial meningitis and may contribute to evidence‐based decisions for antibiotic maintenance and discontinuation.

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Paroxysmal sympathetic hyperactivity during traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of disability, morbidity, and mortality worldwide. Some of the more common etiologies of TBI include closed head injury, penetrating head injury, or an explosive blast head injury. Neuronal damage in TBI is related to both primary injury (caused by mechanical forces), and secondary injury (caused by the subsequent tissue and cellular damages). Recently, it has been well established that Paroxysmal Sympathetic Hyperactivity (PSH), also known as "Sympathetic Storm", is one of the main causes of secondary neuronal injury in TBI patients. The clinical manifestations of PSH include recurrent episodes of sympathetic hyperactivity characterized by tachycardia, systolic hypertension, hyperthermia, tachypnea with hyperpnea, and frank diaphoresis. Given the diverse manifestations of PSH and its notable impact on the outcome of TBI patients, we have comprehensively reviewed the current evidence and discussed the pathophysiology, clinical manifestations, time of onset and duration of PSH during TBI. This article reviews the different types of head injuries that most commonly lead to PSH, possible approaches to manage and minimize PSH complications in TBI and the current prognosis and outcomes of PSH in TBI patients.

Heparin-Induced Fever in Neurointensive Care Unit: A Rarity Yet a Possibility

Fever is considered a protective response having multitude of benefits in terms of enhancing resistance to infection, recruiting cytokines to the injured tissue, and promoting healing. In terms of an injured brain, this becomes a double-edged sword triggering an inflammatory cascade resulting in secondary brain injury. It is important to identify the etiology so that corrective measures can be taken. Here we report a case of persistent fever in a patient with Guillain-Barré syndrome, which was probably due to heparin. This is the first report of heparin-induced fever in a neurocritical care setting and third report overall.

Risk Factors for Intravenous Propacetamol-Induced Blood Pressure Drop in the Neurointensive Care Unit: A Retrospective Observational Study

BACKGROUND

Intravenous propacetamol is commonly used to control fever and pain in neurocritically ill patients in whom oral administration is often difficult. However, several studies reported that intravenous propacetamol may cause blood pressure drop. Thus, we aimed to investigate the occurrence and risk factors for intravenous propacetamol-induced blood pressure drop in neurocritically ill patients.

METHODS

This retrospective study included consecutive patients who were administered intravenous propacetamol in a neurointensive care unit at a single tertiary academic hospital between April 2013 and June 2020. The exact timing of intravenous propacetamol administration was collected from a database of the electronic barcode medication administration system. Blood pressure drop was defined as a systolic blood pressure below 90 mm Hg or a decrease by 30 mm Hg or more. Blood pressure, pulse rate, and body temperature were collected at baseline and within 2 h after intravenous propacetamol administration. The incidence of blood pressure drop was evaluated, and multivariable logistic regression analysis was performed to identify risk factors for blood pressure drop events.

RESULTS

A total of 16,586 instances of intravenous propacetamol administration in 4916 patients were eligible for this study. Intravenous propacetamol resulted in a significant decrease in systolic blood pressure (baseline 131.1 ± 17.8 mm Hg; within 1 h 124.6 ± 17.3 mm Hg; between 1 and 2 h 123.4 ± 17.4 mm Hg; P < 0.01). The incidence of blood pressure drop events was 13.5% within 2 h after intravenous propacetamol. Older age, lower or higher baseline systolic blood pressure, fever, higher Acute Physiology and Chronic Health Evaluation II score, and concomitant administration of vasopressors/inotropes or analgesics/sedatives were significant factors associated with the occurrence of blood pressure drop events after intravenous propacetamol administration.

CONCLUSIONS

Intravenous propacetamol can induce hemodynamic changes and blood pressure drop events in neurocritically ill patients. This study identified the risk factors for blood pressure drop events. On the basis of our results, judicious use of intravenous propacetamol is warranted for neurocritically ill patients with risk factors that make them more susceptible to hemodynamic changes.

A new paper-based biosensor for therapeutic drug monitoring

Tacrolimus is one of the most effective and prevalent drugs used to combat vascularized composite allotransplantation rejection. We have fabricated a rapid and easy-to-use six-layer paper based microfluidic device using the principles of competitive immunoassays and vertical flow microfluidics for colorimetric detection of tacrolimus in a small volume of blood.

Protocol Adherence in the Intensive Care Unit for the Management of Adult Patients Admitted with Acute Aneurysmal Subarachnoid Hemorrhage

Background There are recognized protocols that exist for management with minimal data regarding protocol adherence. We conducted a retrospective analysis of aneurysmal subarachnoid hemorrhage (aSAH) to determine whether the level of protocol adherence varied based on patient demographics or specific aspects of management.

Materials and Methods All cases of aSAH admitted to a tertiary-level intensive care unit (ICU) from 2014 to 2016 were identified from the Australia and New Zealand Intensive Care Society Core Database as well as the clinical records system. ICU demographic and descriptive data for protocol adherence, were collected from admission to discharge up to 22 days, or until death whichever was earlier.

Results A total of 58 cases of aSAH were registered; mean age was 56.7 years, 70.7% of patients were female, and mean length of stay was 12.6 days. World Federation of Neurosurgical Societies (WFNS) scale was documented more than Fisher grading. Of the 58 cases, 63.7% (37) underwent surgical clipping, with 83.7% (30) patients having this surgery within 48 hours. SBP/MAP were the most consistently recorded observations within protocol ranges, with adherence of 82.4% and 82.1%, respectively. Thirty-two percent of temperature measurements were outside of the normothermic range of 36.5 to 37.5°C with a mean adherence of 47.5% (standard deviation = ±0.24, median = 40). There was no correlation between adherence and patient, disease, or admission factors.

Conclusion This study demonstrated that there was no association between variation in protocol adherence based on age, admission dates, or disease factors including WFNS grade and Fisher scale. Best protocol adherence protocol for the management of aSAH within the ICU was blood pressure control. Areas for improvement were documentation of the WFNS and Fisher grading, and temperature measurement and management.

Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a neurologic emergency that requires immediate patient stabilization and prompt diagnosis and treatment. Early measures should focus on principles of advanced cardiovascular life support. The aneurysm should be evaluated and treated in a comprehensive stroke center by a multidisciplinary team capable of endovascular and, operative approaches. Once the aneurysm is secured, the patient is best managed by a dedicated neurocritical care service to prevent and manage complications, including a syndrome of delayed neurologic decline. The goal of such specialized care is to prevent secondary injury, reduce length of stay, and improve outcomes for survivors of the disease.

Impact of Sleep Deprivation in the Neurological Intensive Care Unit: A Narrative Review

Sleep is fundamental for everyday functioning, yet it is often negatively impacted in critically ill patients by the intensive care setting. With a focus on the neurological intensive care unit (NeuroICU), this narrative review summarizes methods of measuring sleep and addresses common causes of sleep disturbance in the hospital including environmental, pharmacological, and patient-related factors. The effects of sleep deprivation on the cardiovascular, pulmonary, immune, endocrine, and neuropsychological systems are discussed, with a focus on short-term deprivation in critically ill populations. Where evidence is lacking in the literature, long-term sleep deprivation studies and the effects of sleep deprivation in healthy individuals are also referenced. Lastly, strategies for the promotion of sleep in the NeuroICU are presented.

Autonomic Hyperactivity

PURPOSE OF REVIEW

Autonomic hyperactivity is a relatively common consequence of severe acute brain injury and can also be seen with spinal cord and peripheral nerve disorders. This article reviews basic pathophysiologic concepts regarding autonomic hyperactivity, its various forms of clinical presentation, and practical management considerations.

RECENT FINDINGS

Paroxysmal sympathetic hyperactivity is most common after traumatic brain injury but can also occur after other forms of severe acute diffuse or multifocal brain injury. Formal criteria for the diagnosis and severity grading of paroxysmal sympathetic hyperactivity have now been proposed. A growing body of literature is beginning to elucidate the mechanisms underlying this disorder, but treatment remains based on observational data. Our mechanistic understanding of other distinct forms of autonomic hyperactivity, such as autonomic dysreflexia after traumatic spinal cord injury and dysautonomia after Guillain-Barré syndrome, remains rudimentary, yet clinical experience shows that their appropriate management can minimize the risk of serious complications.

SUMMARY

Syndromes of autonomic hyperactivity can result from injury at all levels of the neuraxis. Much more research is needed to refine our understanding of these disorders and guide optimal management decisions.

Temperature control in critically ill patients with fever: A meta-analysis of randomized controlled trials

PURPOSE

Fever is frequently encountered in ICU. It is unclear if targeted temperature control is beneficial in critically ill patients with suspected or confirmed infection. We conducted a systemic review and meta-analysis to answer this question.

METHODS

We systematically reviewed major databases before January 2020 to identify randomized controlled trials (RCTs) that compared antipyretic with placebo for temperature control in non-neurocritical ill adult patients with suspected or confirmed infection. Outcomes of interest were 28-day mortality, temperature level, hospital mortality, length of stay, shock reversal, and patient comfort.

RESULT

13 RCTs enrolling 1963 patients were included. No difference in 28-day mortality between antipyretic compared with placebo (risk ratio [RR] 1.03; 95% CI 0.79-1.35). Lower temperature levels were achieved in the antipyretic group (MD [mean difference] -0.41; 95% CI -0.66 to -0.16). Antipyretic use did not affect the risk of hospital mortality (RR 0.97; 95% CI 0.73-1.30), ICU length of stay (MD -0.07; 95% CI -0.70 to 0.56), or shock reversal (RR 1.11; 95% CI 0.76-1.62).

CONCLUSION

Antipyretic therapy effectively reduces temperature in non-neurocritical ill patients but does not reduce mortality or impact other outcomes.

Seizures at the onset of aneurysmal SAH: epiphenomenon or valuable predictor?

Objective

Seizures at the onset (SAO) of aneurysmal subarachnoid hemorrhage (aSAH) occur in up to one of every five cases. To date, there is no consensus on causal background and clinical value of these early bleeding-related seizures. This study aimed to analyze the predictors and the impact of SAO in aSAH.

Methods

All aSAH patients from the institutional observational cohort (01/2003–06/2016) were retrospectively reviewed. Patients’ charts and emergency protocols from first responders were screened for the occurrence of seizures in the first 24 h after aSAH. Patients’ baseline characteristics and occurrence of post-hemorrhagic complications were analyzed. Outcome endpoints included in-hospital mortality and poor outcome at 6-month follow-up (modified Rankin Scale > 3).

Results

Of 984 patients included in the final analysis, SAO occurred in 93 cases (9.5%) and were independently associated with younger age (< 51 years, p < 0.001), WFNS grade ≥ 4 (p < 0.001), aneurysm characteristics (location at the proximal branch of the anterior cerebral artery [p = 0.037] and irregular sac [p = 0.019]) and admission body temperature > 38.3 ℃ (p = 0.008). There was an association between SAO and early complications (early infarcts [p = 0.004] and primary decompressive craniectomy [p = 0.024]). Only in the subgroup analysis restricted to the younger individuals, SAO independently predicted poor outcome of aSAH (p = 0.002).

Significance

Onset seizures following aSAH are rare and most likely related to the severity of early brain injury. Particularly, younger individuals are not only at higher risk for SAO, but are also prone to poor outcome in case of aSAH accompanied with SAO.

Trial registration number

German clinical trial registry (DRKS, unique identifier: DRKS00008749, 06/09/2015)

Discontinuation of Antibiotics in Patients with Neurological Conditions - A Study on the Impact of an Antimicrobial Stewardship Program (ASP) in a Tertiary Institution

BACKGROUND

Up to 50% of antibiotics are prescribed either unnecessarily or inappropriately in most hospitals worldwide. In the largest tertiary hospital in Singapore, patients with neurological conditions were often initiated on antibiotics for change in mental state or isolated fevers. We hypothesize that Antimicrobial Stewardship Program (ASP) interventions to discontinue empirical antibiotics in neurological patients with no clinical evidence of bacterial infection are safe. The aim of this study was to compare clinical impact and safety outcomes of ASP interventions between accepted and rejected groups.

METHODS

A retrospective review of the ASP database was conducted for all patients admitted to the neurology department in Singapore General Hospital between January 2014 and December 2017. Interventions were followed up and patients were classified into two intervention groups, the accepted and rejected groups. Demographic data, age-adjusted Charlson co-morbidity index, duration of antibiotic therapy, length of hospital stay post-ASP intervention (PLOS), infection-related readmissions and mortality were compared between the two groups. Data were expressed as mean ± standard deviation for continuous variables, and unpaired Student's t-test was performed to determine intergroup differences between mean values.

RESULTS

The ASP team recommended 184 interventions, with an overall acceptance rate of 82.6% (152/184). There was no significant difference in demographics and age-adjusted Charlson co-morbidity index between the two groups. The accepted group had a shorter duration of therapy by 1.67 days (4.99±2.50 days vs. 6.66±2.34 days; P<0.01) and a shorter PLOS by 2 days, although this was not statistically significant (22.5±22.2 days vs. 24.5±51.4 days; P=0.83). There were no significant differences between the two groups in 14-day mortality and readmission rates.

CONCLUSION

In neurological patients with no clinical evidence of bacterial infections, ASP interventions to discontinue empirical antibiotics were not associated with increased mortality and readmissions but were associated with significant reduction in duration of therapy.

Management of Subarachnoid Hemorrhage

Subarachnoid hemorrhage is an often devastating intracranial hemorrhage resulting from acute bleeding into the subarachnoid space. Although its overall incidence is less than that of acute ischemic stroke, sub-arachnoid hemorrhage carries increased risks of both mortality and disability. Although many patients with subarachnoid hemorrhage are transferred to specialty centers, they might initially present to small community-based hospitals. Treatment for these patients is complex, requiring specialized care and knowledge, and various complications can occur quickly and without warning. Therefore, all members of the health care team who care for these patients must understand proper management. Nurses in the intensive care unit play an important role in influencing outcomes, as they are best positioned to recognize neurological decline and provide rapid intervention. This article discusses the anatomy relevant to, and the epidemiology and pathophysiology of, subarachnoid hemorrhage and provides an overview of current evidence and clinical guidelines for managing this brain injury.

Comprehensive Analysis of Temperature in Hospitalized Patients

BACKGROUND

Human body temperature is believed to be linked to clinical diagnoses. However, most of the available data stems from healthy individuals, with no large-scale studies addressing body temperature in the inpatient setting, which is the focus of our study.

MATERIALS AND METHODS

This is a retrospective analysis of a total of 695,107 temperature readings from 16,245 patients hospitalized over a 1-year period at a tertiary medical center, ages 0-105 years, 50% female, with rectal, monotherm, axillary, oral, temporal and tympanic measurement sites. The average temperature (T_ave) per patient and per measurement site was used in all calculations. Descriptive statistics, Student's t-test, and Pearson's correlation were used, where appropriate, with statistical significance set at P < 0.05.

RESULTS

T_ave from all measurement sites was 98.13 ± 0.48(SD)F(36.74 ± 0.27°C). T_ave varied by the site of measurement, in decreasing order highest-to-lowest being rectal, monotherm, axillary, oral, temporal, and tympanic, all of which were higher than the available reported averages for healthy subjects. T_ave decreased as patients' age increased. There was only slight and likely clinically insignificant difference between the sexes. There were differences in T_ave between the intensive care units (ICUs), listed from highest-to-lowest: Neuro ICU, Pediatric ICU, Surgical ICU, Cardiac ICU and Medical ICU. However, there was no difference between all ICU and non-ICU patients.

CONCLUSIONS

Our inpatient data demonstrate that previously identified body temperature trends among healthy subjects are preserved, to an extent, in the inpatient setting. To our knowledge, ours is the first study that evaluates the temperatures of all hospitalized patients at a large tertiary medical center.

Non-infectious Fever After Acute Spinal Cord Injury in the Intensive Care Unit

OBJECTIVE

The aim of the present study is to evaluate the frequency, etiology, risk factors and clinical outcomes in acute traumatic SCI patients who develop fever and to evaluate the relationship between fever and mortality.

DESIGN

Retrospective data were collected between January 2007 and August 2016 from patients diagnosed with persistent fever from SCI cases observed in the ICU.

PARTICIPANTS

Among 5370 intensive care patients, 435 SCI patients were evaluated for the presence of fever. A total of 52 patients meeting the criteria were evaluated.

OUTCOME MEASURES

Fever characteristics were evaluated by dividing the patients into two groups: infectious (group-1) and non-infectious (group-2) fever. Demographic and clinical data, ICU and hospital stay, and mortality were evaluated.

RESULTS

In the patients with noninfectious fever, mortality was significantly higher compared to the group with infectious fever (P < 0.001). Of 52 acute SCI cases, 25 (48.1%) had neurogenic fever that did not respond to treatment in intensive care follow-up, and 22 (88%) of these patients died. Maximal fever was 39.10 ± 0.64 °C in Group-1 and 40.22 ± 1.10 ° C in Group-2 (P = 0.001). There was a significant difference in the duration of ICU stay and hospital stay between the two groups (P = 0.005, P = 0.001, respectively), while there was no difference in the duration of mechanical ventilation between the groups (P = 0.544).

CONCLUSION

This study demonstrates that patients diagnosed with neurogenic fever following SCI had higher average body temperature and higher rates of mortality compared to patients diagnosed with infectious fever.

Procalcitonin levels among patients with fever secondary to severe intracerebral infection. A cross-sectional study

BACKGROUND

Making the differential diagnosis between central fever and infectious fever is critically important among intracerebral hemorrhage patients followed up in intensive care units (ICUs). Serum procalcitonin (PCT) has been found to be a promising biomarker for the initial diagnosis of infection, even before culturing results.

OBJECTIVES

To investigate the relationship between PCT and both fever etiologies and C-reactive protein (CRP) levels among critically ill patients with suspected intracerebral hemorrhage.

DESIGN AND SETTING

Cross-sectional study in a public university hospital in Elazig, Turkey.

METHODS

ICU patients diagnosed with intracerebral hemorrhage and normal procalcitonin levels were included in this study. From clinical assessments and cultures, they were classified as presenting either infectious or central fever. The sensitivity and specificity of PCT and CRP for predicting infection were calculated using a receiver operating characteristic (ROC) curve.

RESULTS

There were 98 ICU patients with diagnoses of intracerebral hemorrhage. The median (interquartile range) PCT levels of patients with infectious and central fever were 4 (0.9-11) and 0.1 (0.1-0.4) ng/ml, respectively, with a statistically significant intergroup difference (P < 0.001). The areas under the ROC curve for predicting infectious or central fever PCT and CRP were 0.958 (P < 0.001) and 0.816 (P < 0.001), respectively. A statistically significant positive correlation was detected between PCT and CRP levels in patients with infectious fever (rho: 0.461; P = 0.003), but not in patients with central fever.

CONCLUSIONS

PCT can possibly be used as a biomarker to differentiate between infectious and central fever among ICU patients.

The impact of hyperthermia after acute carbon monoxide poisoning on neurological sequelae

This study investigated whether hyperthermia within the first 24 h after presentation was associated with long-term neurological outcomes after acute carbon monoxide (CO) poisoning. This retrospective study included 200 patients with acute severe CO poisoning. Hyperthermia (≥ 37.5°C) developed during the first 24 h after presentation in 55 (27.5%) patients, and poor long-term neurological sequelae assessed at 23 months after acute CO poisoning developed in 19.5% of the patients. The incidence of poor long-term neurological outcomes was significantly higher in the hyperthermia group than in the normothermia group. Patients with poor long-term neurological outcomes had higher maximum temperatures than patients with good outcomes. No significant difference was found in the time of hyperthermia onset within the first day according to the neurological outcomes. Hyperthermia (adjusted odds ratio (aOR) 5.009 (95% confidence interval (CI) 1.556-16.126)) and maximum temperature (aOR 2.581 (95% CI 1.098-6.063)) within the first 24 h after presentation to the emergency department were independently associated with poor long-term neurological outcomes. Body temperature measurements, which are easily and noninvasively recorded at the bedside in any facility, help to predict the risk for poor long-term neurological outcomes. This study carefully emphasizes fastidious control of pyrexia, particularly during the early period after acute CO poisoning.

Inflammation, edema and poor outcome are associated with hyperthermia in hypertensive intracerebral hemorrhages

Background and purpose

The deleterious effect of hyperthermia on intracerebral hemorrhage (ICH) has been studied. However, the results are not conclusive and new studies are needed to elucidate clinical factors that influence the poor outcome. The aim of this study was to identify the clinical factors (including ICH etiology) that influence the poor outcome associated with hyperthermia and ICH. We also tried to identify potential mechanisms involved in hyperthermia during ICH.

Methods

We conducted a retrospective study enrolling patients with non‐traumatic ICH from a prospective registry. We used logistic regression models to analyze the influence of hyperthermia in relation to different inflammatory and endothelial dysfunction markers, hematoma growth and edema volume in hypertensive and non‐hypertensive patients with ICH.

Results

We included 887 patients with ICH (433 hypertensive, 50 amyloid, 117 by anticoagulants and 287 with other causes). Patients with hypertensive ICH showed the highest body temperature (37.5 ± 0.8°C) as well as the maximum increase in temperature (0.9 ± 0.1°C) within the first 24 h. Patients with ICH of hypertensive etiologic origin, who presented hyperthermia, showed a 5.3‐fold higher risk of a poor outcome at 3 months. We found a positive relationship (r = 0.717, P < 0.0001) between edema volume and hyperthermia during the first 24 h but only in patients with ICH of hypertensive etiologic origin. This relationship seems to be mediated by inflammatory markers.

Conclusion

Our data suggest that hyperthermia, together with inflammation and edema, is associated with poor outcome only in ICH of hypertensive etiology.

Postinterventional critical care management of aneurysmal subarachnoid hemorrhage

PURPOSE OF REVIEW

Subarachnoid hemorrhage from a ruptured aneurysm (aSAH) is a complex disorder with the potential to have devastating effects on the brain as well as other organ systems. After more than 3 decades of research, the underlying pathophysiologic mechanisms remain incompletely understood and important questions remain regarding the evaluation and management of these patients. The purpose of this review is to analyze the recent literature and improve our understanding of certain key clinical aspects.

RECENT FINDINGS

Growing body of evidence highlights the usefulness of CT perfusion scans in the diagnosis of vasospasm and delayed cerebral ischemia (DCI). Hypervolemia leads to worse cardiopulmonary outcomes and does not improve DCI. The traditional triple H therapy is falling out of favor with hemodynamic augmentation alone now considered the mainstay of medical management. Randomized controlled trials have shown that simvastatin and intravenous magnesium do not prevent DCI or improve functional outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Emerging data using multimodality monitoring has further advanced our understanding of the pathophysiology of DCI in poor grade aSAH.

SUMMARY

The brief review will focus on the postinterventional care of aSAH patients outlining the recent advances over the past few years.

Thermoregulation in brain injury

Different mechanisms explain thermoregulatory dysfunction following ischemic stroke, hemorrhagic stroke, and traumatic brain injury. Temperature instability following brain injury likely involves hypothalamic injury, pathologic changes in cerebral blood flow, metabolic derangement, and a neurogenic inflammatory response. Although targeted temperature management (TTM) exerts pleiotropic effects, the heterogeneity of brain injury has hindered identification of patient subsets most likely to benefit from TTM. Early optimism about TTM's role in brain injury has been tempered by the failure of successive clinical trials to show improved patient outcomes. However, given the deleterious effects of fever, aggressive fever management is still warranted in the critically ill neurologic patient.

Early fever after trauma: Does it matter?

BACKGROUND

Fever is strongly associated with poor outcome after traumatic brain injury (TBI). We hypothesized that early fever is a direct result of brain injury and thus would be more common in TBI than in patients without brain injury and associated with inflammation.

METHODS

We prospectively enrolled patients with major trauma with and without TBI from a busy Level I trauma center intensive care unit (ICU). Patients were assigned to one of four groups based on their presenting Head Abbreviated Injury Severity Scale scores: multiple injuries: head Abbreviated Injury Scale (AIS) score greater than 2, one other region greater than 2; isolated head: head AIS score greater than 2, all other regions less than 3; isolated body: one region greater than 2, excluding head/face; minor injury: no region with AIS greater than 2. Early fever was defined as at least one recorded temperature greater than 38.3°C in the first 48 hours after admission. Outcome measures included neurologic deterioration, length of stay in the ICU, hospital mortality, discharge Glasgow Outcome Scale-Extended, and plasma levels of seven key cytokines at admission and 24 hours (exploratory).

RESULTS

Two hundred sixty-eight patients were enrolled, including subjects with multiple injuries (n = 59), isolated head (n = 97), isolated body (n = 100), and minor trauma (n = 12). The incidence of fever was similar in all groups irrespective of injury (11-24%). In all groups, there was a significant association between the presence of early fever and death in the hospital (6-18% vs. 0-3%), as well as longer median ICU stays (3-7 days vs. 2-3 days). Fever was significantly associated with elevated IL-6 at admission (50.7 pg/dL vs. 16.9 pg/dL, p = 0.0067) and at 24 hours (83.1 pg/dL vs. 17.1 pg/dL, p = 0.0025) in the isolated head injury group.

CONCLUSION

Contrary to our hypothesis, early fever was not more common in patients with brain injury, though fever was associated with longer ICU stays and death in all groups. Additionally, fever was associated with elevated IL-6 levels in isolated head injury.

LEVEL OF EVIDENCE

Prognostic and Epidemiological study, level III.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids with seizures and central pyrexia, in a patient requiring tracheal intubation and mechanical ventilation: A case report

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) has been described in multiple case reports since it was first described in the literature in 2010. The patient described is a 54-year-old man with no significant medical history who presented with ataxia, diplopia and hearing and taste disturbances. His GCS reduced to the point at which he required intubation and he was treated for 50 days on an intensive care unit. The patient's course also includes seizures, first described in 2014, and central pyrexia, which has not been previously described in case reports of CLIPPERS. Intravenous methylprednisolone resulted in a rapid and significant recovery; neurological rehabilitation is ongoing 10 months from diagnosis. The importance of recognition of unusual radiological findings and rapid treatment cannot be overemphasised in improving patient's long-term outcomes.

Exam 4 Questions

A 73-year-old male with a history of hypertension and hyperlipidemia is currently in the stroke unit after suffering a right middle cerebral artery infarct. His symptoms started 2 h prior to arrival at the hospital, and tPA was administered. The patient is plegic on the left side and with mild dysarthria, but is otherwise neurologically intact. His labwork is within normal limits. Which of the following describes the optimal deep venous thrombosis (DVT) prophylaxis regimen for this patient?A.

Wait 6 h post tPA, then administer unfractionated heparin (UFH) along with intermittent pneumatic compression (IPC)

B.

Wait 24 h post tPA, then administer UFH along with IPC

C.

Wait 6 h post tPA, then administer low molecular weight heparin (LMWH) along with IPC

D.

Wait 24 h post tPA, then administer LMWH along with IPC

E.

IPC only for the first 72 h, then LMWH or UFH after obtaining follow-up imaging

All of the following causes of acute encephalitis have the matching characteristic radiological features except:A.

Autoimmune limbic encephalitis: T2/FLAIR hyperintensity in the mesial temporal lobes

B.

Cytomegalovirus: T2/FLAIR hyperintensity in the subependymal white matter

C.

JC virus: T2/FLAIR hyperintensity in the parieto-occipital lobes and corpus callosum

D.

Herpes simplex virus type 1: restricted diffusion in frontal/temporal lobes and insular cortex

E.

Varicella zoster: T2/FLAIR hyperintensity in the brainstem

Which of the following categorizations is most accurate regarding acute respiratory distress syndrome (ARDS) in the setting of subarachnoid hemorrhage (SAH)?A.

Non-neurogenic, non-cardiogenic

B.

Neurogenic, non-cardiogenic

C.

Neurogenic, cardiogenic

D.

Non-neurogenic, cardiogenic

E.

None of the above accurately reflect ARDS in SAH

A 52-year-old female is admitted to the ICU with a Hunt-Hess 1, modified Fisher 2 subarachnoid hemorrhage. Her past medical history is significant for hypertension, diabetes mellitus, and chronic renal insufficiency. She undergoes craniotomy for surgical clipping of an anterior cerebral artery aneurysm, and does not experience any additional complications. Two weeks later, she begins complaining of left calf pain, and a lower extremity sonogram demonstrated a proximal deep venous thrombosis (DVT). The patient weighs 60 kg. Her laboratory values are as follows: sodium 142 mEq/L, potassium 3.4 mEq/L, carbon dioxide 18 mEq/L, blood urea nitrogen (BUN) 70 mg/dL, and serum creatinine 2.5 mg/dL. What would be the optimal treatment for this patient’s proximal DVT?A.

Unfractionated heparin infusion for at least 5 days concomitantly with warfarin therapy

B.

Low molecular weight heparin 60 mg twice a day for at least 5 days concomitantly with warfarin therapy

C.

Fondaparinux 7.5 mg daily for 5 days followed by warfarin therapy

D.

Apixaban 10 mg twice daily for 7 days followed by 5 mg twice daily

E.

Rivaroxaban 15 mg twice daily for 21 days followed by 20 mg once daily

All of the following are currently implicated in uremic encephalopathy except:A.

Derangements in cerebral metabolism

B.

Alterations in the blood-brain barrier

C.

Accumulation of circulating toxins

D.

Imbalance of endogenous neurotransmitters

E.

Recurrent lobar hemorrhages

A 70-year-old female is hospitalized with a recent ischemic infarct. As part of stroke core measures, you obtain a hemoglobin A1c of 10.0. What is an approximate estimation of this patient’s average blood glucose level over the last several months?A.

70 mg/dL

B.

100 mg/dL

C.

130 mg/dL

D.

190 mg/dL

E.

240 mg/dL

A 28-year-old female with no known past medical history is in the ICU in status epilepticus, with anti-N-methyl D-aspartate (NMDA) receptor antibodies isolated in the cerebrospinal fluid. Which of the following is most likely to identify the root cause of her illness?A.

Transvaginal ultrasound

B.

Contrast-enhanced CT of the chest

C.

Contrast-enhanced CT of the brain

D.

Virtual colonography

E.

Thorough examination of the skin, particularly in sun-exposed areas

A 17-year-old male with no significant past medical history collapses during a high school football game, and goes into cardiac arrest. He did not have any complaints earlier in the day. The patient is brought to a nearby hospital, where is he resuscitated, intubated, and transferred to the ICU for further management. The patient is currently undergoing therapeutic hypothermia, and a work-up is underway to determine the cause of his sudden collapse. Which of the following is the most likely diagnosis?A.

Rupture of a previously undiagnosed cerebral aneurysm

B.

Hypertrophic cardiomyopathy

C.

Commotio cordis

D.

Severe hyponatremia and cerebral edema

E.

Brugada syndrome

A 31-year-old female at 38 weeks gestation is currently hospitalized for the treatment of preeclampsia. Due to her medical condition, her obstetrician is currently considering induced labor. At which point will this patient no longer be at risk for developing frank seizure activity as a result of her condition?A.

48 h postpartum

B.

1 week after delivery

C.

2 weeks after delivery

D.

4 weeks after delivery

E.

6 weeks after delivery

A 38-year-old male with no prior medical history presents to the emergency department with fever and severe headaches for several days. A CT scan of the brain is unremarkable, and the results of a lumbar puncture are pending. What is the most appropriate empiric antimicrobial regimen at this time?A.

Cefazolin and vancomycin

B.

Ceftriaxone and vancomycin

C.

Ceftriaxone, vancomycin and ampicillin

D.

Piperacillin/tazobactam and vancomycin

E.

Meropenem and vancomycin

The majority of intramedullary spinal cord neoplasms are:A.

Astrocytomas

B.

Meningiomas

C.

Metastatic lesions

D.

Ependymomas

E.

Hemangioblastomas

Which of the following derived parameter formulas is correct?A.

Cardiac index = cardiac output x body surface area

B.

Stroke volume = cardiac output/heart rate

C.

Systemic vascular resistance = 80 × (mean arterial pressure/cardiac output)

D.

Pulmonary vascular resistance = 80 × (mean pulmonary artery pressure/cardiac output)

E.

All of the above are correct

A 23-year-old female marathon runner is currently in the ICU after suffering from heat stroke following an outdoor run on a particularly hot summer day. She was initially delirious in the emergency department, but progressed to coma and respiratory failure requiring mechanical ventilation. Her oral temperature is 42.1 °C. Which of the following would be most effective in reducing this patient’s severe hyperthermia?A.

Regularly scheduled alternating acetaminophen and ibuprofen

B.

Spraying room temperature water on the patient, followed by fanning

C.

Ice water immersion

D.

Dantrolene sodium, 2.5 mg/kg

E.

Application of ice packs to the groin and axilla

Hyperinsulinemia-euglycemia (HIE) therapy may be useful for toxicity related to which of the following?A.

Tricyclic antidepressants

B.

Calcium channel blockers

C.

Aspirin

D.

Digoxin

E.

Lithium

A 71-year-old female with a history of alcohol abuse is currently intubated in the ICU following a catastrophic spontaneous left basal ganglia hemorrhage with resultant herniation. You have just declared her brain dead. The patient’s family agrees to make her an organ donor, and the organ donation coordinator requests you initiate levothyroxine therapy. Which of the following benefits would be expected with this treatment?A.

Increase the number of solid organs available for transplant

B.

Eliminate the need for hepatic biopsy prior to liver transplant

C.

Eliminate the need for cardiac catheterization prior to heart transplant

D.

Eliminate the need for bronchoscopy prior to lung transplant

E.

Reduce the need for supplementation of sodium, potassium, calcium, and magnesium

Which of the following is not an element of the Full Outline of Unresponsiveness (FOUR) score?A.

Eye opening

B.

Respiratory function

C.

Brainstem reflexes

D.

Motor response

E.

Verbal response

A 23-year-old female is currently in the ICU with status asthmaticus. She was initially on noninvasive positive pressure ventilation, with an arterial blood gas (ABG) as follows: pH 7.13, pCO₂ 60 mmHg, PaO₂ is 61 mmHg, HCO₃ 24 mmol/L, and oxygen saturation of 90%. She is given continuous inhaled albuterol, intravenous steroids, and magnesium sulfate. She subsequently becomes more lethargic and is intubated, with settings as follows: volume assist-control, rate of 12 breaths/min, tidal volume of 500 cc, PEEP of 5 cm H₂O, and FiO₂ of 50%. Peak airway pressure is 50 cm H₂O and plateau pressure is 15 cm H₂O. A stat portable chest x-ray shows hyperinflation with no pneumothorax. A repeat ABG after 30 min of invasive ventilation shows the following: pH of 7.24, pCO₂ 49 mmHg, PaO₂ 71 mmHg, HCO₃ is 25 mmol/L. Which of the following should be performed next?A.

Increase rate to 16

B.

Increase tidal volume to 600 cc

C.

Initiate bicarbonate infusion

D.

Switch to pressure assist-control

E.

Maintain current settings

Which of the following mechanisms is implicated in super-refractory status epilepticus?A.

Influx of proinflammatory molecules

B.

Upregulation of NMDA receptors

C.

Upregulation of molecular transport molecules

D.

Downregulation of GABA receptors

E.

All of the above

A 85-year-old male with a history nephrolithiasis, mild dementia, and alcohol abuse presented to the emergency department after a fall from standing, and was found to a right holohemispheric subdural hematoma. His clot was evacuated successfully, in spite of his oozing diathesis in the operating room (INR on arrival was 1.4 with a platelet count of 88 × 10³/μL). His serum transaminases are twice the normal value, and he has had refractory chronic hyponatremia. He has had three convulsions during this week of hospitalization, in spite of levetiracetam therapy at 1.5 g twice a day. Over the past 24 h, he has had a marked increase in agitation. He has also just had a 5-s run of non-sustained ventricular tachycardia, and his systolic blood pressure is now 85 mmHg. You are considering discontinuing his levetiracetam and starting a new agent. Which of the following would be the best choice in this scenario?A.

Carbamazepine

B.

Phenytoin

C.

Valproate

D.

Lacosamide

E.

Topiramate

A 65-year-old male with a history of COPD on rescue albuterol and ipratropium is diagnosed with myasthenia gravis, and started on an acetylcholinesterase inhibitor. He returns several days later complaining of increased salivation and worsening bronchial secretions in the absence of fevers, purulent sputum, or increasing dyspnea. These symptoms are not relieved by use of his albuterol. On exam, he has slightly decreased air movement throughout both lung fields without any clear wheezing, no focal rales, and a normal inspiratory to expiratory ratio. Which treatment option is most likely to be beneficial?A.

Increase frequency of short-acting ß₂ agonist use

B.

Add a standing long-acting inhaled ß₂ agonist

C.

Add glycopyrrolate as needed

D.

Add inhaled corticosteroids

E.

Add oral systemic corticosteroids

Regarding states of impaired consciousness, which of the following statements regarding arousal and awareness is correct?A.

Coma: intact arousal, but impaired awareness

B.

Minimally conscious state: impaired arousal and impaired awareness

C.

Persistent vegetative state: intact arousal, but impaired awareness

D.

Locked-in state: intact arousal, but impaired awareness

E.

All of the above are correct

A 62-year-old female is currently in the ICU following craniotomy for clipping of a cerebral aneurysm. Postoperatively, she is noted to have an oxygen saturation of 92% on 50% non-rebreather face mask, and her respiratory rate is 32 breaths/min. She denies chest pain. Her blood pressure is 96/72 mmHg and heart rate is 120 beats/min. Nimodipine has been held according to blood pressure parameters. A portable chest x-ray shows hazy opacities bilaterally, and bedside echocardiogram shows decreased left ventricular systolic function with apical, septal, lateral, anterior, anteroseptal and inferolateral wall akinesis, along with apical ballooning. Which of the following should be performed next?A.

Intubate the patient and begin mechanical ventilation

B.

Call urgent cardiology consult for cardiac catheterization

C.

Start noninvasive positive airway pressure ventilation

D.

Administer broad spectrum antibiotics

E.

Administer albuterol and systemic corticosteroids

Which of the following is the most common etiology of acute spinal cord ischemia and infarction?A.

Atherosclerotic disease

B.

Rupture of an abdominal aortic aneurysm

C.

Degenerative spine disease

D.

Cardioembolic events

E.

Systemic hypotension in the setting of other disease processes

A 62-year-old female with a history of coronary artery disease has just been admitted to the ICU with a left-sided spontaneous basal ganglia hemorrhage. The patient takes 325 mg of aspirin daily at home, and you are considering platelet transfusion. Which of the following has been demonstrated regarding platelet transfusion in this setting?A.

Improved chances of survival to hospital discharge

B.

Decreased hospital length-of-stay

C.

Improved chances of survival at 3 months

D.

Improved modified Rankin scale at 3 months

E.

None of the above

Which of the following therapies has been shown to decrease the incidence of delayed cerebral ischemia (DCI) in the setting of subarachnoid hemorrhage (SAH)?A.

Atorvastatin

B.

Magnesium

C.

Methylprednisolone

D.

Nicardipine

E.

None of the above

A 70-year-old male with a history of diabetes, hypertension, and cigarette smoking (one pack per day for the last 40 years) is currently in the ICU with a COPD exacerbation. This is his third exacerbation this year, and was discharged from the hospital only 3 weeks prior. On your examination, he is alert, his breathing is labored, and he has rales at the right lung base. His vital signs are as follows: blood pressure 90/60 mmHg, heart rate 120 beats per minute, respirations 28 per minute, and temperature 38.3 °C. His oxygen saturation on 50% face mask is 93%, and his most recent PCO₂ is 55 mmHg. Labs are notable for the following: white blood cell count 14.4 × 10⁹/L with 90% neutrophils, blood urea nitrogen (BUN) 30 mg/dL, serum creatinine 1.2 mg/dL, and glucose 240 mg/dL. Ketones are negative. He is currently on noninvasive positive pressure ventilation at 10/5 cm H₂O and 50% FiO₂, and broad spectrum antibiotics have been administered. An hour later, the nurse pages you because his heart rate is now 140 beats per minute and irregular, blood pressure is 85 systolic, oxygen saturation is 85%, and he is minimally responsive. You now hear bilateral rales, most prominently in the right lung base, and scattered wheezes. Which of the following should be performed next?A.

Increase inspiratory pressure to 15 and FiO₂ to 100%

B.

Start a continuous diltiazem infusion and give intravenous furosemide

C.

Start a continuous phenylephrine infusion targeting a mean arterial pressure (MAP) > 65

D.

Give 125 mg of solumedrol and administer albuterol via nebulizer

E.

Intubate the patient and initiate mechanical ventilation

A 57-year-old male with a history of epilepsy is currently in the stroke unit following a large right middle cerebral artery infarction. A nasogastric tube has been inserted, and 24 h continuous enteral feeds have been initiated. The patient is currently on 100 mg of phenytoin every 8 h for seizure prophylaxis. Which of the following measures should be taken to prevent the patient from developing subtherapeutic phenytoin levels?A.

Change to 18 h tube feeds, and only administer phenytoin at night

B.

Change to 18 h tube feeds, and only administer phenytoin twice daily

C.

Switch from standard to hydrolyzed tube feeds

D.

Switch from standard to glycemic control tube feeds

E.

Hold tube feeds for 2 h before and after phenytoin administration

A 37-year-old female presents to the emergency department with approximately 2 weeks of progressively worsening clumsiness and drastic mood swings. Her past medical history is significant only for Crohn’s disease, for which she takes both natalizumab and infliximab. A contrast-enhanced CT scan of her head is performed, revealing hypodense, non-enhancing lesions in the cortical white matter of the frontal and parietal lobes. Despite treatment, the patient expires 1 month later. Which of the following is true regarding the most likely diagnosis?A.

The diagnosis may be confirmed via CSF analysis

B.

The pathologic process spares oligodendrocytes

C.

It is a prion-based disease

D.

The condition is universally fatal despite treatment

E.

All of the above

A 58-year-old female presents to the emergency department with dry cough, fever and rapidly progressive dyspnea over 1 week. She has a history of rheumatoid arthritis (RA) and is maintained on weekly methotrexate and daily prednisone (which was increased to 30 mg starting 1 month ago for an acute flare). She takes no other medications. Her vital signs are as follows: blood pressure 100/70 mmHg, heart rate 110 beats/min, respiratory rate 20 breaths/min, and temperature 38.0 °C. In the ED she develops progressive hypoxemia with oxygen saturation 92% on 100% nonrebreather, and is increasingly diaphoretic. She is emergently intubated, and a chest x-ray post intubation shows extensive bilateral lung opacities. Which of the following should be administered at this time?A.

Ceftriaxone and azithromycin

B.

Vancomycin and piperacillin-tazobactam

C.

Vancomycin, cefepime, and fluconzole

D.

Ceftriaxone, levofloxacin, and trimethoprim-sulfamethoxazole

E.

Tigecycline only

A 45-year-old woman undergoes uncomplicated transsphenoidal resection of a pituitary macroadenoma. She appears well hydrated and is not complaining of excessive thirst. Post-operatively, she is noted to have increased urine output. Serum sodium is 137 mEq/L, and serum osmolarity is 275 mOsm/kg. What is the most likely cause of her polyuria?A.

Syndrome of inappropriate antidiuretic hormone

B.

Diabetes insipidus

C.

Cerebral salt wasting

D.

Fluid mobilization

E.

All of the above are equally likely

A 36-year-old female with a recent lumbar puncture to rule out subarachnoid hemorrhage is now complaining of a severe headache unlike anything she has experienced previously. She reports her headache is worse when standing, and better upon lying flat. She is otherwise neurologically intact. All of the following medications may be beneficial in this scenario except:A.

Acetaminophen

B.

Ibuprofen

C.

Caffeine

D.

Aminophylline

E.

Methylprednisolone

Which of the following is the most common overall cause of acute myocardial infarction?A.

Coronary dissection

B.

Plaque rupture

C.

Imbalance between oxygen demand and supply across a fixed obstruction

D.

Coronary vasospasm

E.

Ischemia related to hypotension and decreased perfusion

A 78-year-old male is in the ICU recovering from sepsis and pneumonia. He was just recently extubated after 2 days of mechanical ventilation and sedation with a fentanyl infusion. Over the ensuing days, he develops worsening abdominal distention, poor bowel sounds, and no stool output. CT scan reveals significant colonic distention, but no mass or obstruction. Records demonstrate a normal routine colonoscopy performed 6 weeks ago. You have appropriately hydrated the patient, corrected any electrolyte abnormalities, placed a rectal tube, withheld all opiates, and given intravenous erythromycin, but to no avail. Abdominal x-rays continue to demonstrate marked cecal dilatation greater than 12 cm in diameter. What is the next best appropriate therapy for this patient?A.

Neostigmine

B.

Naloxone

C.

Metoclopromide

D.

Surgical consultation for hemicolectomy

E.

Endoscopic percutaneous cecostomy tube placement

Which of the following is the most common cerebral vascular malformation in the general population?A.

AV malformation

B.

Dural AV fistula

C.

Developmental venous anomaly

D.

Cavernous malformation

E.

Vein of Galen malformation

A 49-year-old female with a history of acute lymphoblastic leukemia and recent subcutaneous cerebrospinal fluid (CSF) reservoir placement presents to the emergency department with fever, chills, and increased confusion for the past 3 days. Her CSF reservoir was last accessed 1 week ago. A thorough work-up reveals no other obvious infectious source, and there is concern for CSF reservoir-associated meningitis. Which of the following is the most likely causative organism?A.

Coagulase-negative staphylococci

B.

Propionobacterium acnes

C.

Methicillin-resistant Staphylococcus aureus

D.

Klebsiella pneumoniae

E.

Neisseria meningitidis

A 47-year-old woman presents to the emergency department with headache, nausea, and vomiting. Non-contrast head CT is performed, revealing subarachnoid blood in the right Sylvian fissure, and conventional angiography reveals the presents of a large right-sided MCA aneurysm. The patient undergoes successful surgical clipping of her aneurysm, and is being observed in the ICU. On admission, the patient’s serum sodium was 142 mEq/L and the hematocrit was 37%; by the seventh post-operative day, the serum sodium is 127 mEq/L and the hematocrit is 44%. Bedside ultrasonography demonstrates an IVC diameter of approximately 0.9 cm. Which of the following interventions would be least reasonable at this time?A.

Fludrocortisone, 0.2 mg twice a day

B.

2% hypertonic saline, infused peripherally

C.

3% hypertonic saline, infused centrally

D.

Sodium chloride oral tablets

E.

1500 mL daily fluid restriction

Which of the following is true regarding central (non-infectious) fever?A.

Less common in subarachnoid hemorrhage

B.

More common versus infectious fever

C.

Earlier onset versus infectious fever

D.

Easier to confirm versus infectious fever

E.

All of the above

Flaccid paralysis is most commonly associated with which of the following forms of encephalitis?A.

West Nile

B.

Varicella zoster

C.

Rabies

D.

Herpes simplex

E.

Epstein-Barr

Which of the following would not be considered appropriate therapy for heparin-induced thrombocytopenia (HIT)?A.

Discontinuation of heparin products alone

B.

Danaparoid

C.

Fondaparinux

D.

Argatroban

E.

All of the above are acceptable treatment options

A 45-year-old male with severe blunt traumatic brain injury (TBI) from a motor vehicle collision suffered a ventricular fibrillation cardiac arrest at the time of injury with return of spontaneous circulation (ROSC) in the field after endotracheal intubation and one dose of epinephrine. On arrival to the emergency department, no regional wall motion abnormalities were noted on surface echocardiography and no ST segment changes were seen on the presenting EKG. Head CT revealed cerebral contusions but no extra-axial mass lesions. The patient is now in the ICU and found to be comatose without sedation. Mild therapeutic hypothermia to 33° is being considered in the management of this post-arrest patient. Which of the following statements is true?A.

Mild therapeutic hypothermia is contraindicated due to the risk of induced epilepsy

B.

Mild therapeutic hypothermia is contraindicated with any intracranial pathology on CT imaging

C.

Mild therapeutic hypothermia does not induce a clinically significant coagulopathy

D.

Patients who have sustained ROSC after an arrest associated with TBI do not benefit from therapeutic hypothermia

E.

Endovascular cooling is superior to surface cooling in young patients with ROSC

A 35-year-old male is in the intensive care unit following resection of a large right-sided meningioma. He is currently intubated and sedated on a continuous fentanyl infusion. The nurse calls you to the bedside due to concerns over “unusual ventilator waveforms”. Upon arrival, you note the following (see Image 1). What is the best way to describe this phenomenon?A.

Reverse triggering

B.

Double triggering

C.

Breath stacking

D.

Missed triggering

E.

None of the above; normal ventilator waveforms are present

Comparison of Two Surface Cooling Devices for Temperature Management in a Neurocritical Care Unit

Fever increases mortality and morbidity and length of stay in neurocritically ill patients. Various methods are used in the neuroscience intensive care unit (NSICU) to control fever. Two such methods involve the Arctic Sun hydrogel wraps and the Gaymar cooling wraps. The purpose of our study was to compare these two methods in neurocritical care patients who had temperature >37.5°C for more than three consecutive hours and that was refractory to standard treatments. Data of patients requiring cooling wraps for treatment of hyperthermia at an NSICU at an academic, tertiary referral center were retrospectively reviewed. The average temperature before cooling was 38.5°C ± 0.38°C and 38.4°C ± 0.99°C for the Gaymar and Arctic Sun groups, respectively (p = 0.89). The Gaymar group took on average 16 ± 21.9 hours to reach goal temperature, whereas the Arctic Sun group took 2.22 ± 1.39 hours (p = 0.08). The average time outside of the target temperature was 57.0 ± 58.0 hours in the Gaymar group compared with 13.7 ± 17.1 hours in the Arctic Sun group (p = 0.04). Average duration of using the cooling wraps was similar between the two groups; 81.8% of patients had rebound hyperthermia in the Gaymar group compared with 20% in the Arctic Sun group (p = 0.0089). The Arctic Sun group had a nonsignificant increased incidence of shivering compared with the Gaymar group (40% vs. 18.18%, p = 0.36). We found that Arctic Sun surface cooling device was more efficient in attaining the target temperature, had less incidence of rebound hyperthermia, and was able to maintain normothermia better than Gaymar cooling wraps. The incidence of shivering tended to be more common in the Arctic Sun group.

Preventive Antibiotics and Delayed Cerebral Ischaemia in Patients with Aneurysmal Subarachnoid Haemorrhage Admitted to the Intensive Care Unit

INTRODUCTION

Delayed cerebral ischemia (DCI) is an important contributor to poor outcome after aneurysmal subarachnoid haemorrhage (aSAH). Development of DCI is multifactorial, and inflammation, with or without infection, is one of the factors independently associated with development of DCI and poor outcome. We thus postulated that preventive antibiotics might be associated with a reduced risk of DCI and subsequent poor outcome in aSAH patients.

METHODS

We performed a retrospective cohort-study in intensive care units (ICU) of three university hospitals in The Netherlands. We included consecutive aSAH patients with minimal ICU stay of 72 h who received either preventive antibiotics (SDD: selective digestive tract decontamination including systemic cefotaxime or SOD: selective oropharyngeal decontamination) or no preventive antibiotics. DCI was defined as a new hypodensity on CT with no other explanation than DCI. Hazard ratio's (HR) for DCI and risk ratio's (RR) for 28-day case-fatality and poor outcome at 3 months were calculated, with adjustment (aHR/aRR) for clinical condition on admission, recurrent bleeding, aneurysm treatment modality and treatment site.

RESULTS

Of 459 included patients, 274 received preventive antibiotics (SOD or SDD) and 185 did not. With preventive antibiotics, the aHR for DCI was 1.0 (95% CI 0.6-1.8), the aRR for 28-day case-fatality was 1.1 (95% CI 0.7-1.9) and the aRR for poor functional outcome 1.2 (95% CI 1.0-1.4).

CONCLUSIONS

Preventive antibiotics were not associated with reduced risk of DCI or poor outcome in aSAH patients in the ICU.

Predictors of Prolonged Hospitalization in Patients with Fever

Objective: The study was conducted to analyze the predictors of prolonged hospitalization in patients with fever.

Patients and Methods: This was a prospective cohort study conducted from July - December 2015 at Ayub Teaching Hospital, Pakistan. Convenience sampling was used to enroll the patients who visited the hospital during the study duration. A sample size of 115 patients was calculated. It included patients who presented with a new onset fever which started in the last month, and the cause of fever was undiagnosed at the time of admission. Critical patients were excluded. Data for more than 30 variables was collected on a pro forma. Univariate regression methods were used to analyze the data in the Statistical Package for Social Sciences (SPSS), version 23.

Results: A total of 115 patients were analyzed. Males constituted 66/115 (57.4%). The mean age for patients was 43.6 years (standard deviation (SD) = 20.2). On admission, low platelet counts (p = 0.001), high erythrocyte sedimentation rate (ESR) counts (p = 0.007), a high total leukocyte count (TLC) (p = 0.029), and involvement of nervous (p = 0.021), cardiovascular (p = 0.04), respiratory (p = 0.043), gastroenterological (p = 0.042), hematological (p = 0.028), or urogenital system (p = 0.016) were associated with a longer stay in the hospital.

Conclusion: Patients with an undiagnosed and new onset fever will have a longer hospital stay if, on admission, they have low platelet counts, a higher ESR, a high TLC, or involvement of nervous, cardiovascular, respiratory, gastrointestinal, hematological, or urogenital systems. An early identification of risk factors can lead to better treatment and may also lead to a decreased hospital stay.

Pyrexia: aetiology in the ICU

Elevation in core body temperature is one of the most frequently detected abnormal signs in patients admitted to adult ICUs, and is associated with increased mortality in select populations of critically ill patients. The definition of an elevated body temperature varies considerably by population and thermometer, and is commonly defined by a temperature of 38.0 °C or greater. Terms such as hyperthermia, pyrexia, and fever are often used interchangeably. However, strictly speaking hyperthermia refers to the elevation in body temperature that occurs without an increase in the hypothalamic set point, such as in response to specific environmental (e.g., heat stroke), pharmacologic (e.g., neuroleptic malignant syndrome), or endocrine (e.g., thyrotoxicosis) stimuli. On the other hand, pyrexia and fever refer to the classical increase in body temperature that occurs in response to a vast list of infectious and noninfectious aetiologies in association with an increase in the hypothalamic set point. In this review, we examine the contemporary literature investigating the incidence and aetiology of pyrexia and hyperthermia among medical and surgical patients admitted to adult ICUs with or without an acute neurological condition. A temperature greater than 41.0 °C, although occasionally observed among patients with infectious or noninfectious pyrexia, is more commonly observed in patients with hyperthermia. Most episodes of pyrexia are due to infections, but incidence estimates of infectious and noninfectious aetiologies are limited by studies with small sample size and inconsistent reporting of noninfectious aetiologies. Pyrexia commonly triggers a full septic work-up, but on its own is a poor predictor of culture-positivity. In order to improve culturing practices, and better guide the diagnostic approach to critically ill patients with pyrexia, additional research is required to provide more robust estimates of the incidence of infectious and noninfectious aetiologies, and their relationship to other clinical features (e.g., leukocytosis). In the meantime, using existing literature, we propose an approach to identifying the aetiology of pyrexia in critically ill adults.

Neurogenic Fever

Fever is a relatively common occurrence among patients in the intensive care setting. Although the most obvious and concerning etiology is sepsis, drug reactions, venous thromboembolism, and postsurgical fevers are all on the differential diagnosis. There is abundant evidence that fever is detrimental in acute neurologic injury. Worse outcomes are reported in acute stroke, subarachnoid hemorrhage, and traumatic brain injury. In addition to the various etiologies of fever in the intensive care setting, neurologic illness is a risk factor for neurogenic fevers. This primarily occurs in subarachnoid hemorrhage and traumatic brain injury, with hypothalamic injury being the proposed mechanism. Paroxysmal sympathetic hyperactivity is another source of hyperthermia commonly seen in the population with traumatic brain injury. This review focuses on the detrimental effects of fever on the neurologically injured as well as the risk factors and diagnosis of neurogenic fever.

Clinical factors and incidence of prolonged fever in neurosurgical patients

AIMS AND OBJECTIVES

To describe the incidence of prolonged fever in patients admitted to the neurosurgery department, and the corresponding risk indicators.

BACKGROUND

Prolonged fever was defined as a temperature higher than 38·3°C lasting more than five days. Prolonged fever is a common phenomenon and could lead to worsened outcomes in specific patient groups, especially for those with brain injury. However, the studies on prolonged fever in neurosurgical patients are limited and insufficient.

DESIGN

A retrospective observational study.

METHODS

Retrospective data were collected from 1 January 2014 to 31 December 2014, at the neurosurgical department of a large teaching hospital. We performed univariate and multivariate analyses to identify independent indicators for prolonged fever vs. short-term fever.

RESULTS

Among 2845 patients, prolonged fever occurred in 466 (16%). The older patients were associated with longer duration of mechanical ventilation and hospital stay. It predominantly occurred in patients with subarachnoid haemorrhage (SAH) and traumatic brain injury. Patients receiving antibiotic treatment tended to manifest prolonged fever more frequently. Multivariate analysis revealed that the use of antibiotics, central venous catheter and prolonged mechanical ventilation were independent risk predictors for prolonged fever. Patients diagnosed with brain tumour seemed to be not associated with prolonged fever.

CONCLUSIONS

Prolonged fever is the common complication in neurosurgical patients. The risks of prolonged fever in patients are attributed to antibiotic therapy, use of central venous catheter and prolonged mechanical ventilation. Indicators of prolonged fever are helpful for better identification of high-risk patients and fever control.

RELEVANCE TO CLINICAL PRACTICE

A better reveal on the epidemiology and predictable factors of prolonged fever in neurosurgical patients will provide a better understanding on those patients who are most at risk, and therefore contribute to fever control and better outcome.

Case Studies in Neurocritical Care

The practice of neurocritical care encompasses multiple acute neurologic and neurosurgical diseases and requires detailed knowledge of neurology and critical care. This article presents 5 cases that illustrate just some of the conditions encountered in the daily practice of neurocritical care and exemplify some of the common diagnostic, therapeutic, and prognostic challenges facing the neurointensivist. Life-threatening medical complications after severe acute ischemic stroke, seizures and extreme agitation from autoimmune encephalitis, refractory seizures after subdural hemorrhage, neurologic and systemic complications related to aneurysmal subarachnoid hemorrhage, and status epilepticus after cardiac arrest are discussed in this article.